Well you have quite a rifle there. AS you probably know the 45-70 was replaced as our U.S. service cartridge 111 years ago. That gives you and Idea of its staying power. Marlin chambered it in the 1895 rifle in 1972 I think. The rifle has caught on again and this time with Hunters in Africa where it dropped two Cape Buffalo with one shot and has been used a few times to take the Big Six Game animals of Africa. You can find out more about its new loads by going to the Garret Gartridge webb site and read the testimonials. I have one in the Marlin and one in the NEF single shot. Loaded to the hilt it will get your attention right away. I would get a good reloader such as the RCBS starter kit Or even one of the Lee Kits. Go to Midway USA for a good place to start looking. The 300 grain bullets are best for deer size game with the 350 Speer and 350 Hornady Round nose for Elk and bigger bears. If you have any more questions feel free to Email me and I will do my best to help you out..